High speed sheet path gating system

ABSTRACT

A print media sheets path selection system with a repositionable gate for selectably directing even rapidly sequentially moving sheets with small inter-sheet time gaps into different output paths with different gate positions. This gate is partially or entirely repositionable to an opposite gate position for providing a different output path for the next sheet while a portion of the prior sheet is still moving past the gate. That may be accomplished by providing a low limited force engagement of the part of the gate engaging the sheet, allowing that sheet to slide past at least the tip of the gate without damage, by a compliant gate tip or other low gate force system. Thereby the repositioning of the gate between its different gate positions is not limited to the short time gap between the sequential sheets and can be accomplished less critically and/or with lower force and acceleration.

Disclosed in the embodiments herein is a high speed sheet path gating system that can be used to selectively divert even rapidly moving closely spaced apart flimsy print media sheets into a selected one of separate plural sheet paths without sheet damage or an expensive high-powered gate actuator. Traditional sheet path selector gates are not actuated until after an adequate time delay or sensor input to insure that that the trial edge of the previous sheet last diverted has fully passed the gate. With the present embodiments, the gate can start to be actuated even before the trail edge passes the gate. The disclosed embodiments have gate deflector fingers with a low mass flexible and/or very lightly spring loaded sheet engaging tip end.

Conventional active sheet path diverter gates are very common and have been well known in the art for many years in commercial xerographic and other printer paper paths. Thus, their numerous possible exemplary embodiments need not be cited or discussed herein. That includes the use of such gates in “TIPP” systems of tandem integrated plural print engines such as Xerox Corp. U.S. Pat. Nos. 7,024,152 issued Apr. 4, 2006; 6,959,165 issued Aug. 8, 2005; and 5,568,246 issued Oct. 22, 1996, incorporated by reference. Such active gates typically function to selectively divert sequentially moving sheets from an upstream paper path (which may be called a sheet path) into a selected downstream sheet path or paths, in various possible locations. Typically such gates are actuated between their respective different gate positions by a linear or rotary solenoid, stepper motor, or otherwise, directly or via lever actuators, cams, etc. These are also well known and need not be described in any detail herein. Such active gates should not be confused with passive gates, such as fixed flexed plastic flaps, which can only divert sheets into a single sheet path.

Higher speed sheet path decision gates have become of greater concern with higher speed (faster PPM rate) sheet feeders, and/or printing systems having more than one sheet feeders combining their outputs into a single sheet path, and/or partially shared paper paths and/or other integration of two or more marking engines into a combined printing system having a correspondingly higher total printing output rate.

For example (but not limited thereto) an active sheet path diverter gate anywhere in a sheet path any of these or other sheet transporting systems that might require gated sheet path diversions for selected sheets moving in a sheet path at 400 sheets per minute into one of two or more other selectable sheet paths would present serious challenges to conventional sheet diverter gates. In the case of a 50 millisecond inter-sheet time gap, for example, even if the variability of that inter-sheet time gap is limited, the gate would needs to change state to deflect sheets into a different path within only approximately 10 milliseconds.

A specific feature of the specific embodiments disclosed herein is to provide a moving print media sheets path selection system comprising a print media sheets input path and at least first and second different print media sheet output paths and a print media sheets gating system for directing selected said moving print media sheets into a selected one of said at least first and second different print media sheet output paths, wherein said print media sheets gating system has a repositionable gate repositionable by a gate actuating system between at least a first gate position directing said print media sheets into said first print media sheet output path and a second gate position directing said print media sheets into said second print media sheet output path, wherein said repositionable gate has a compliant outer sheet engaging tip portion, and a gate actuating system is connected to said repositionable gate for actuating said repositionable gate while a print media sheet is still in said print media sheets gating system and before said print media sheet has passed said compliant outer sheet engaging tip portion of said repositionable gate so that said repositionable gate may be at least partially repositioned between said first and second gate positions while said print media sheet is still partially in said print media sheets gating system with said print media sheet being slidably engaged with low force by said compliant outer sheet engaging tip portion of said repositionable gate.

Further specific features disclosed in the embodiments herein, individually or in combination, include those wherein said compliant outer sheet engaging tip portion of said repositionable gate is sufficiently compliant to not interfere with the movement of a print media sheet moving through said print media sheets gating system even after said repositionable gate has been substantially repositioned between said first and second gate positions; and/or wherein said compliant outer sheet engaging tip portion of said repositionable gate is flexible relative to the rest of said repositionable gate and of low mass relative the rest of said repositionable gate so as not to interfere with the movement of a print media sheet moving through said print media sheets gating system even after said repositionable gate has been substantially repositioned between said first and second gate positions; and/or wherein said compliant outer sheet engaging tip portion of said repositionable gate is sufficiently flexible to exert only a light load on a print media sheet and of sufficiently low mass to rapidly reposition between said first and second gate positions after a print media sheet in said print media sheets gating system has passed said compliant outer sheet engaging tip portion of said repositionable gate; and/or wherein said repositionable gate other than said compliant outer sheet engaging tip portion comprises at least one rigid pivotal extending finger pivotally driven by said gate actuating system; and/or wherein said compliant outer sheet engaging tip portion of said repositionable gate is hinge-connected with a light spring loading to the rest of said repositionable gate; and/or wherein said print media sheets are moving in said print media sheets input path with a small inter-sheet time gap between said print media sheets, wherein said gate actuating system is actuated while a print media sheet is still in said print media sheets gating system and prior to said inter-sheet time gap and before said print media sheet has passed said compliant outer sheet engaging tip portion of said repositionable gate; and/or a method of print media sheets path selection from a print media sheets input path in which plural print media sheets are rapidly sequentially moving with small inter-sheet gaps between the trail edge of one sheet and the lead edge of a next sequential sheet, by rapidly directing selected said print media sheets into a selected one of at least first and second different print media sheet output paths with a sheet path gate repositionable by a gate actuating system between at least a first gate position directing said print media sheets into said first print media sheet output path and a second gate position directing said print media sheets into said second print media sheet output path, comprising actuating said gate actuating system to start said repositioning of said sheet path gate between said first and second gate positions while at least a portion of a print media sheet is slidably engaged by at least the tip portion of said sheet path gate and before said small inter-sheet gap reaches said sheet path gate, and completing said repositioning of said sheet path gate between said first and second gate positions after the trail edge of that print media sheet has passed the tip portion of said sheet path gate; and/or wherein the outer tip portion of said sheet path gate is flexible with low force relative to the rest of said sheet path gate; and/or wherein the outer tip portion of said sheet path gate is deflectable by said print media sheets moving against it from said sheets input path; and/or wherein the outer tip portion of said sheet path gate is sufficiently compliant and low mass to exert only a light load on a print media sheet and be rapidly repositioned between said first and second gate positions as soon as the trailing edge of a print media sheet passes said outer tip portion of said sheet path gate; and/or a method of print media sheets paths selection with a repositionable gate selectably directing rapidly sequentially moving sheets having a brief time gap between the trail edge of one sheet and the lead edge of the next sheet into selected different output paths with different gate positions, wherein said gate has a rigid main body and semi-independently deflectable and sheet compliant tip portion, and wherein said main body of said gate is repositioned between said different gate positions while at least a portion of a sheet is still in said gate, but wherein said gate tip completes said repositioning between said different gate positions after the trail edge of the sheet has moved past said gate, so that said repositioning of said gate between said different gate positions is not limited to said brief time gap between said trail edge of one sheet and the lead edge of the next sheet; and/or a method of print media sheets paths selection by repositioning a gate between at least first and second different gate positions to selectably direct sheets rapidly sequentially moving through said gate with only a brief time gap between the trail edge of a first sheet and the lead edge of the next sheet into selected different output paths determined by said different gate positions, wherein said gate is repositioned between said first and second different gate positions for said selected different output path of said next sheet while at least a portion of said first sheet is still moving past said gate by providing a low force sliding engagement of said gate against said moving first sheet during at least part of the time period of the repositioning of said gate between said first and second gating positions for diverting said next sheet into said other sheet output, at least a substantial portion of said repositioning of said gate between said first and second different gate positions occurring substantially outside of said brief time gap between said trail edge of said first sheet and the lead edge of the next sheet; and/or wherein said repositioning of said gate between said first and second gating positions is by a force limited gate actuating system; and/or a moving print media sheets path selection system comprising a print media sheets input path and at least first and second different print media sheet output paths and a print media sheets gating system for directing selected said moving print media sheets into a selected one of said at least first and second different print media sheet output paths, wherein said print media sheets gating system has a repositionable gate repositionable by a gate actuating system between at least a first gate position directing said print media sheets into said first print media sheet output path and a second gate position directing said print media sheets into said second print media sheet output path, wherein a gate actuating system is operatively connected to said repositionable gate for actuating said repositionable gate while a print media sheet is still in said print media sheets gating system and before said print media sheet has passed said repositionable gate so that said repositionable gate may be at least partially repositioned between said first and second gate positions while said print media sheet is still partially in said print media sheets gating system with said print media sheet being slidably engaged with low force by said repositionable gate, said gate actuating system comprising a gate actuator and a force-limiting spring connection between said gate actuator and said repositionable gate.

The disclosed system may be operated and controlled by appropriate operation of conventional control systems. It is well known and preferable to program and execute imaging, printing, paper handling, and other control functions and logic with software instructions for conventional or general purpose microprocessors, as taught by numerous prior patents and commercial products. Such programming or software may, of course, vary depending on the particular functions, software type, and microprocessor or other computer system utilized, but will be available to, or readily programmable without undue experimentation from, functional descriptions, such as those provided herein, and/or prior knowledge of functions which are conventional, together with general knowledge in the software or computer arts. Alternatively, the disclosed control system or method may be implemented partially or fully in hardware, using standard logic circuits or single chip VLSI designs.

The terms “reproduction apparatus” “marking engine” or “printer” as used herein broadly encompasses various printers, copiers or multifunction machines or systems, xerographic or otherwise, unless otherwise defined in a claim. The term “sheet” and/or “print media”, as used herein refers to a usually flimsy physical sheet of paper, plastic, or other suitable physical substrate for images, whether precut or web fed. The term “gate” as used herein, can, as is well known in this art, include gates with plural transversely spaced “fingers,” and thus plural “tips,” even though “gate tip” is expressed in the singular for convenience in the claims and elsewhere herein.

As to specific components of the subject apparatus or methods, or alternatives therefor, it will be appreciated that, as is normally the case, some such components are known per se in other apparatus or applications, which may be additionally or alternatively used herein, including those from art cited herein. For example, it will be appreciated by respective engineers and others that many of the particular component mountings, component actuations, or component drive systems illustrated herein are merely exemplary, and that the same novel motions and functions can be provided by many other known or readily available alternatives. All cited references, and their references, are incorporated by reference herein where appropriate for teachings of additional or alternative details, features, and/or technical background. What is well known to those skilled in the art need not be described herein.

Various of the above-mentioned and further features and advantages will be apparent to those skilled in the art from the specific apparatus and its operation or methods described in the examples below, and the claims. Thus, they will be better understood from this description of these specific embodiments, including the drawing figures (which are approximately to scale) wherein:

FIG. 1 is a schematic frontal view of one example of a high speed, less time window operational critical, sheet path diverter gating system with a compliant gate tip for selecting between either one of two exemplary sheet output paths for sheets entering from an input path;

FIG. 2 is the same as FIG. 1 but illustrating the flexing of the compliant gate tip still engaging the sheet in the gating system even though the gate is being initially activated to move to its alternate position for selection of the other output path;

FIG. 3 is a slightly different embodiment, with spring-loaded compliant gate tip, in the same operating position of the gate of FIG. 2;

FIGS. 4 and 5 are schematic timing chart examples for illustratively demonstrating the different electrical actuation signal timings and time window with the above embodiments in FIG. 5 versus the much more restricted actuating time window for an exemplary conventional gate in FIG. 4;

FIG. 6 is one example of an otherwise known TIPP plural printer printing system (see the above-incorporated TIPP patents) illustrating some exemplary possible sheet paths locations in which any of the embodiments of a less time window critical and/or high speed sheet path diverter gating system could be utilized in a TIPP system; and

FIGS. 7 and 8 schematically illustrate, similarly to FIGS. 1-3, two different sheet diverter gating positions for two different sheet outputs without requiring a flexible gate tip but similarly providing a low force engagement of the gate against a moving sheet that is already passing the gate so that the gate may meanwhile already be actuated to its other gating position for diverting the next sheet into the other sheet output.

Describing now in further detail the exemplary embodiments with reference to the Figs, the embodiment shown in FIGS. 1 and 2 will be described first, since most of that description will also apply to the embodiment of FIG. 3 with the differences noted below. A moving print media sheets path selection system 10 is provided in both embodiments comprising a print media sheets input path 12, at least first and second different print media sheet output paths 14 and 16, and a print media sheets gating system (20 in FIGS. 1 and 2, and 30 in FIG. 3) for directing selected moving print media sheets 18 into a selected one of the exit or output paths 14 and 16. For illustrative clarity FIG. 1 is shown without any sheet in the gating system area (just a sheet 18 entering the system). FIGS. 2 and 3 show the gate in transition with a sheet 18 therein. Conventional sheet feeding nips of feed rollers and mating idlers may be provided in the sheet paths, as illustrated in these Figs or otherwise.

Referring to FIG. 1 for convenience, the gating system 20 has a repositionable gate 22 repositionable by a known or other suitable gate actuating system 24 (such as a rotary solenoid or stepper motor, or a linear solenoid and interconnecting gate lever rotator). This gate actuating system 24 moves the gate 22 between at least a first gate position 26 directing the. sheets into the first sheet output path 14, and a second gate position 28 directing the sheets into the second sheet output path 16. The incoming sheet lead edge and.trail edge position and/or timing relative to the gate 22 may be conventionally calculated from conventional upstream sheet path sensors, such as 19 illustrated here.

Of particular interest here, most of this repositionable gate 22 is conventionally substantially rigid, including its connection to the gate actuating system 24 which pivots the gate 22 about its pivot axis 22A between its gate positions 26 and 28. However, this gate 22 here unconventionally has a minor and low mass outer end tip portion 22B (at the end opposite from its pivot axis 22A). This gate tip 22B provides a low force sheet-compliant sheet-engaging member.

This allows the gate actuating system 24 to be actuated much earlier and over a much longer time period than a normal such gate. That is, electrical power may be applied to the gate actuating system 24 (under the control of the controller 100) to initially actuate the movement of the rigid main body of the gate 22 while a print media sheet 18 is still in the print media sheets gating system 20. That is, before that.print media sheet 18 has even passed by the compliant sheet engaging tip portion 22B of the repositionable gate 22. Thus, as shown in FIG. 2, the main body of the gate 22 may be already partially or even entirely moved from its first gate position 26 to its second gate position 28 while the print media sheet 18 is still partially in the gating system 20. This is possible because, as is shown in FIG. 2, the tip portion 22B of the gate 22 can angularly flex relative to the rest of the gate 22 with sufficiently low force compliance to not interfere with the continued movement of the print media sheet 18 then moving over it, and to not damage that sheet 18, even though the main body of the gate 22 has already been repositioned toward the other gate position 28 (which will direct the next sheet to the other sheet output path 16). The flexible gate tip or tips 22B can flex relative to the rest of the gate 22 to ride under the sheet in the gate area as shown. This gate tip 22B can similarly flex in the opposite direction to ride on top of a sheet during an opposite gate 22 movement from gate position 28 to gate position 24. This tip flexing can continue until the sheet 18 trail edge has cleared the gate tip 22B, at which point the gate tip 22B is released from any sheet engagement force can automatically flip back into its normal position aligned with the rest of the gate 22 and fully moved therewith to the other gate position.

In the embodiment of FIG. 3, its print media sheets gating system 30 has a repositionable gate 32 with springs 34 loaded tip 32A to provide a compliant tip. It can provide the same above-noted and other functions. That is, it shows an alternate gate tip configuration utilizing a lightly sprung gate tip 32A. In the particular operative position illustrated in FIG. 3 this gate 32 is being started to pivot up towards gate position 28 while the trail edge of a sheet 18 is still passing through the gate area over the gate 32 into the output path 14 by deflecting the gate tip 32A downwardly. Thus, by the time the trail edge of that sheet 18 has passed the gate tip 32A the gate 32 will have had considerable extra time to be fully repositioned into its alternate gate position 26 for directing the very next sheet into the other sheet output path 16.

To recap, these exemplary high speed sheet path diverter gating systems can be used to rapidly divert high speed sheets into one of two or more exit or output paths by using a moving gate with a flexible tip or a very lightly sprung tip that allows the gate to be actuated while the previous sheet is still passing through the gate area. Traditional gates must wait until the system is sure that the previous sheet trail edge has completely passed the gate before actuating the gate in the inter-sheet space to move the gate into another alternate output path gating position. This contrast is illustrated by the considerable time period difference between T1 in FIG. 4 and T2 in FIG. 5, as will be discussed further below.

In all of the embodiments herein, as illustrated in the example of FIG. 5, the gate can be actuated well before the previous sheet trail edge passes the gate. The flexible gate tip can flex with low force to temporarily ride against the trailing area of that previous sheet while it is still in the gate. This relies upon the fact that even most coated print media sheets can withstand sheet engaging surface forces without marking if those forces are sufficiently light. With the gate forces spread out laterally across the sheet, it is anticipated that the allowable spring force for a flexible gate tip engaging a sheet could be as high as that seen with heavy weight media engaged by typical curved baffles.

Since the gate tip has a very low mass it will quickly un-flex and move to the alternate gate position along with the rest of the gate as soon as the trail edge of that previous sheet passes the gate tip. Note that the low mass gate tip is the only mass that moves at a different rate than the rest of the gate after the sheet trail edge passes it.

These exemplary gates with a flexible tip or a very lightly sprung tip can be actuated while the previous sheet is still passing through the gate area, as shown in the timing chart of FIG. 5. In contrast, with traditional gates, as shown in the timing chart of FIG. 4, the previous sheet trail edge must pass the gate before actuating it. Otherwise the sheet could be ‘pinched’ by the gate, causing sheet damage and/or a sheet feeding jam. In both FIGS. 4 and 5, “A” represents a first sheet lead edge passing the gate tip, “B” represents a first sheet trail edge passing the gate tip, “D” represents the second (next) sheet lead edge passing the gate tip, and “E” represents the second sheet trail edge passing the gate tip. In the lower time track the time portion “C” in FIG. 4 illustrates the very brief time window T1 in which that conventional gate must fully change its position within the small time gap between B and D. Furthermore, B and D can vary somewhat, making the safely available time window T1 even smaller, as show by its dashed line end positions. In contrast, the gate actuation time period “C1” in FIG. 5 can occur much more slowly within the entire much longer time period T2 starting well before time point B. Only the flexible gate tip flexure C2 into its final new gate position need occur within the small time gap between B and D in FIG. 5.

For systems with very short inter-document times (closely spaced apart rapidly moving sheets), it can be. problematic to design a gate with a suitably short gate switching time, such as T1 in FIG. 4, occurring entirely within that very short inter-document gap time. With the disclosed systems, the gate is actuated before the previous sheet trail edge passes the gate. Since the gate tip has a low mass and low force resistance to deflection by the sheet (high compliance), the gate tip can at first ride on the surface of the previous sheet and then continue to move to the alternate gate position with the rest of the already moving gate as soon as the trail edge of that sheet passes the gate tip. Thus, this gate can effectively switch positions more quickly than a conventional fully rigid gate by having a much longer switching time, such as within time period T2 in FIG. 5. That is, electrical power may be applied to the gate driving solenoid, or other gate mover, substantially before the sheet leaves the gate. This allows for much more time for the gate to fully change its effective gating positions without having to undesirably reduce the overall gate mass, and without having to undesirably increasing the gate driving force, acceleration/deceleration, and noise, and/or changing to a more expensive faster acting gate driving system.

Any risk of potential image damage to previously printed sheets (including sheets being duplexed) from scraping or wear of the gate tip against the sheet could be further reduced by optimization of the selected gate tip materials, geometry and/or compliance forces. For example, by providing a low friction plastic gate with an integral hinge formed by a reduced thickness area between the main body of the gate and the tip portion, and/or by a TEFLON®, diamond or other low-friction surface coating for the gate tip surfaces engaging the sheet.

Turning now to the FIGS. 7 and 8 third embodiment 40 of a print media sheets gating system, it also has the above and other advantages and features. It similarly shows two different sheet diverter gating positions (FIG. 7 relative to FIG. 8) for selectably diverting the next sheet in the incoming sheet stream from the sheet input path 12 into one of two different exemplary sheet outputs 14 and 16. It does not require a flexible gate tip, but similarly provides a low force sliding engagement of a moving sheet that is already passing by the gate towards one sheet output, so that the gate may meanwhile already be, within that same time period, actuated toward or fully into its other gating position for diverting the very next incoming sheet into the other sheet output. Here, the entire gate 42 including the tip end 42A may be integral and substantially rigid, but is preferably of low mass and relatively short length, and as shown the gate tip 42A is only lightly spring loaded against a sheet 18 that it engages in the gate area. In this example that is accomplished by a light, low force limiting, leaf spring 45 connecting between the gate actuating solenoid 44 and the gate. pivot 46, instead of a conventional rigid link or lever arm. This insures a low force sliding engagement of the gate 40 against the moving first sheet during the time period of the repositioning the gate between its first and second gating positions for diverting the next sheet into the other sheet output, so that the repositioning of the gate between the first and second different gate positions is not limited to the brief time gap between the trail edge of that sheet and the lead edge of the next sheet, like a normal gate. Thus, providing the advantages discussed above with reference to FIG. 5 versus FIG. 4, etc. The repositioning of the gate between its different gate positions is not limited to the short time gap between the sequential sheets and can. be accomplished less critically and/or with lower force and acceleration.

The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others. Unless specifically recited in a claim, steps or components of claims should not be implied or imported from the specification or any other claims as to any particular order, number, position, size, shape, angle, color, or material. For example, the gate tips are shown with- pointed ends here for schematic illustrative convenience, but could be rounded with these embodiments in these systems. 

1. A moving print media sheets path selection system comprising a print media sheets input path and at least first and second different print media sheet output paths and a print media sheets gating system for directing selected said moving print media sheets into a selected one of said at least first and second different print media sheet output paths, wherein said print media sheets gating system has a repositionable gate repositionable by a gate actuating system between at least a first gate position directing said print media sheets into said first print media sheet output path and a second gate position directing said print media sheets into said second print media sheet output path, wherein; said repositionable gate has a compliant outer sheet engaging tip portion, and a gate actuating system is connected to said repositionable gate for actuating said repositionable gate while a print media sheet is still in said print media sheets gating system and before said print media sheet has passed said compliant outer sheet engaging tip portion of said repositionable gate so that said repositionable gate may be at least partially repositioned between said first and second gate positions while said print media sheet is still partially in said print media sheets gating system with said print media sheet being slidably engaged with low force by said compliant outer sheet engaging tip portion of said repositionable gate.
 2. The moving print media sheets path selection system of claim 1, wherein said compliant outer sheet engaging tip portion of said repositionable gate is sufficiently compliant to not interfere with the movement of a print media sheet moving through said print media sheets gating system even after said repositionable gate has been substantially repositioned between said first and second gate positions.
 3. The moving print media sheets path selection system of claim 1, wherein said compliant outer sheet engaging tip portion of said repositionable gate is flexible relative to the rest of said repositionable gate and of low mass relative the rest of said repositionable gate so as not to interfere with the movement of a print media sheet moving through said print media sheets gating system even after said repositionable gate has been substantially repositioned between said first and second gate positions.
 4. The moving print media sheets path selection system of claim 1, wherein said compliant outer sheet engaging tip portion of said repositionable gate is sufficiently flexible to exert only a light load on a print media sheet and of sufficiently low mass to rapidly reposition between said first and second gate positions after a print media sheet in said print media sheets gating system has passed said compliant outer sheet engaging tip portion of said repositionable gate.
 5. The moving print media sheets path selection system of claim 1, wherein said repositionable gate other than said compliant outer sheet engaging tip portion comprises at least one rigid pivotal extending finger pivotally driven by said gate actuating system.
 6. The moving print media sheets path selection system of claim 1, wherein said compliant outer sheet engaging tip portion of said repositionable gate is hinge-connected with a light spring loading to the rest of said repositionable gate.
 7. The moving print media sheets path selection system of claim 1, wherein said print media sheets are moving in said print media sheets input path with a small inter-sheet time gap between said print media sheets, wherein said gate actuating system is actuated while a print media sheet is still in said print media sheets gating system and prior to said inter-sheet time gap and before said print media sheet has passed said compliant outer sheet engaging tip portion of said repositionable gate.
 8. A method of print media sheets path selection from a print media sheets input path in which plural print media sheets are rapidly sequentially moving with small inter-sheet gaps between the trail edge of one sheet and the lead edge of a next sequential sheet, by rapidly directing selected said print media sheets into a selected one of at least first and second different print media sheet output paths with a sheet path gate repositionable by a gate actuating system between at least a first gate position directing said print media sheets into said first print media sheet output path and a second gate position directing said print media sheets into said second print media sheet output path, comprising: actuating said gate actuating system to start said repositioning of said sheet path gate between said first and second gate positions while at least a portion of a print media sheet is slidably engaged by at least the tip portion of said sheet path gate and before said small inter-sheet gap reaches said sheet path gate, and completing said repositioning of said sheet path gate between said first and second gate positions after the trail edge of that print media sheet has passed the tip portion of said sheet path gate.
 9. The method of print media sheets path selection of claim 8, wherein the outer tip portion of said sheet path gate is flexible with low force relative to the rest of said sheet path gate.
 10. The method of print media sheets path selection of claim 8, wherein the outer tip portion of said sheet path gate is deflectable by said print media sheets moving against it from said sheets input path.
 11. The method of print media sheets path selection of claim 8, wherein the outer tip portion of said sheet path gate is sufficiently compliant and low mass to exert only a light load on a print media sheet and be rapidly repositioned between said first and second gate positions as soon as the trailing edge of a print media sheet passes said outer tip portion of said sheet path gate.
 12. A method of print media sheets paths selection with a repositionable gate selectably directing rapidly sequentially moving sheets having a brief time gap between the trail edge of one sheet and the lead edge of the next sheet into selected different output paths with different gate positions, wherein said gate has a rigid main body and semi-independently deflectable and sheet compliant tip portion, and wherein said main body of said gate is repositioned between said different gate positions while at least a portion of a sheet is still in said gate, but wherein said gate tip completes said repositioning between said different gate positions after the trail edge of the sheet has moved past said gate, so that said repositioning of said gate between said different gate positions is not limited to said brief time gap between said trail edge of one sheet and the lead edge of the next sheet.
 13. A method of print media sheets paths selection by repositioning a gate between at least first and second different gate positions to selectably direct sheets rapidly sequentially moving through said gate with only a brief time gap between the trail edge of a first sheet and the lead edge of the next sheet into selected different output paths determined by said different gate positions, wherein said gate is repositioned between said first and second different gate positions for said selected different output path of said next sheet while at least a portion of said first sheet is still moving past said gate by providing a low force sliding engagement of said gate against said moving first sheet during at least part of the time period of the repositioning of said gate between said first and second gating positions for diverting said next sheet into said other sheet output, at least a substantial portion of said repositioning of said gate between said first and second different gate positions occurring substantially outside of said brief time gap between said trail edge of said first sheet and the lead edge of the next sheet.
 14. The method of print media sheets paths selection by repositioning a gate between at least first and second different gate positions of claim 13, wherein said repositioning of said gate between said first and second gating positions is by a force limited gate actuating system.
 15. A moving print media sheets path selection system comprising a print media sheets input path and at least first and second different print media sheet output paths and a print media sheets gating system for directing selected said moving print media sheets into a selected one of said at least first and second different print media sheet output paths, wherein said print media sheets gating system has a repositionable gate repositionable by a gate actuating system between at least a first gate position directing said print media sheets into said first print media sheet output path and a second gate position directing said print media sheets into said second print media sheet output path, wherein; a gate actuating system is operatively connected to said repositionable gate for actuating said repositionable gate while a print media sheet is still in said print media sheets gating system and before said print media sheet has passed said repositionable gate so that said repositionable gate may be at least partially repositioned between said first and second gate positions while said print media sheet is still partially in said print media sheets gating system with said print media sheet being slidably engaged with low force by said repositionable gate, said gate actuating system comprising a gate actuator and a force-limiting spring connection between said gate actuator and said repositionable gate. 